Means for facilitating the starting of internal-combustion engines.



. F. PURDY. MEANS FOR FACILITATING .THE STARTING OI INTERNAL COMBUSTION ENGINES. I

APPLICATION FILED 1320.23, 1908.

976,493. Patented Nov. 22; 1910.

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. F. PURDY. MEANS FOR' FACILITATING THE STARTING OF INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. 23, 1908. 976,493, Patented Nov. 22, 1910.

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UNITED STATE s PATENT OFFICE.

FREDERICK PURDY, OF KENOSHA, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO KATE E. JEFFERY, CHARLES T. JEFFERY, AND HAROLID'W. JEFFERY, EXECU TORS 0F THOMAS B. JEFFERY, DECEASED.

MEANS FOR FACILITATING THE STARTING 0F INTERNAL-COMBUSTION ENGINES.

To all whom it may concern:

Be it known that L'FR DERICK PURDY, a citizen of the United States, residing at Kenosha, county of Kenosha, State of WIS- consin, have invented a certainnew and u'sefnl Improvement in Means for Facilitating the Starting of Internal-Combustion Engines, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same,

reference being had to the accompanying drawings, which form a part of thisfspecification.

.My invention has. for its object the pro- 'ision of a simple arrangement wherebythe exhaust valves of multi cylinder engines which normally open between the ends of,

detailed description taken in connection with the accompanying drawings, 'wherein:'

Figure l is a side elevation of a four cylinder gas engine containing my invention; Fig. 2 is a section through one of the cylinders illustratin the normal operation of the enginegand ig. 3 .is a fragmentary section illustrating the operation in stopping the engine.

Referring to the drawings, A represents a four-cylinder internal combustion engine, the cylinders being indicated at B, C, D and E, respectively. b, c, a? and e are the casings for the several exhaust valves, these casings communlcatmg with a common 'exhaust conduit F. All these parts may take any usual pr preferred forms, since they are simply lllustrative of multl-cylinder lnternal combustion engines in general.

G is the usual cam shaft having thereon cams g, g, g, g for lifting the exhaust valves through thelr stems 6 ,9 ,11 and 6 H is a shaft arranged parallel with the cam shaft and having fingers h h h h each of which is adapted normally to lie between specification of Letters Patent.

Application filed December 23', 1908. Serial No. 468,889

.could explode: then there will be Patented Nov. 22, 1910.

one of the. cams and the corresponding valve stem as indicated in Fi .2.

In Fig.2 the piston in the cylinder'E is shown as approaching the end of its power stroke, the crank I connected thereto being still aconsiderable angular distance fromthe lower center. The exhaust valve E has just been lifted from its seat so as to' ermit some of the power charge to escape, t is be ing the usual condition in many types of engines. Now suppose that the operator, de-

siring to stop the engine, interrupted the fir ing circuit before .the charge in the cylinder equal charges in the cylinder E and inthe other cylinder. ofthe engine wherein compression is taking-place. As a result, the engine will seek a position of equilibrium which would ordinarily be that wherein the pistons are midway of their strokes. However, if there is considerable oscillation of the pistons before coming to rest, the iston E may reach and even pass, the position in which it is shown in Fig. 2 before returning to its posi-' tion of rest. In such case a portion of the position .of equilibrium would be such that power charge would ordinarily be lost, the f the piston in the power cylinder could notexert a maximum leverage on the crank, and the engine would be unable to start under its own power, making it necessary to crank in order to set the engine in operation. By making the shaft H revolubleso as to enable it to withdraw the fingers-partly from between the cams and the valve stems, and.

properly shaping the fingers, then, upon stopping the engine, the exhaust valve on the power cylinder can be prevented from opening even though the reliminary oscillation of the engine prece ing the condition of rest be great enough to carry the piston 'to or beyond the positionindicated in Fig.

2. Consequently there will be no loss of.

gasfrom the power cylinder and the engine will always come to rest with the powerpiston in the most advantageous position "for starting.

' The fingers h may take any desired ehape thus, they may have a bulging portion It so located that when the fingers occupy the position shown in Fig. 2 the exhaust valves will be operated in the normal way; while,

when the shaft H is oscillated to bring the fingers to the positions indicated in Fig.

3, the cams are unable to lift the exhaust valves,

In order to insure that the charge in the power cylinder will not be exploded when the exhaust mechanism is rendered inopera-. tive, there may be in the firing circuit a .switch which is' controlled by the shaft H or its operating lever H K indicates a portion of the firing circuithave described in detail only a single practi-' cal arrangement for preventing the exhaust valves from opening when the engine is stopped, and thereby avoiding loss of pressure in the power cylinder but I desire to cover the various other mechanical expedients which may be adopted toeifect this end as will be evident from the terms employed in the definitions of my invention constituting the appended claims.

Having now described my. invention, what I claim as new and desire to secure by Let ters Patent is 1. In an internal combustion engine, a plurality of engine cylinders, pistons in said cylinders, exhaust valves, valve-actuating cams, movable members arranged between said cams and said valves, said members having two positions in one of which the cams are permitted to open said exhaust valves between the ends of. the power strokes .strokes of said pistons or of the pistons and in the other of which the cams are prevented from opening the exhaust valves before the pistons reach the ends of their power strokes.

2. In an internal combustion. engine, a plurality of engine cylinders, pistons in said cylinders, exhaust valves, valve-actuating cams, movable fingers arranged between said valves and said cams, said fin ers having portions which will permit t e exhaust valves to be opened between the ends of the ower strokes of said istons when said portions lie between the va ves and the canis, said fingers also having reduced portions, proportion to prevent the cams from openmg said valves before the pistons reach the ends of their working strokes and means for actuating said fingers to brin either the first-mentioned portions thereo or the last-mentioned portions thereof between the cams and the valves so'asto permit the valves to be opened between the endsof the power prevent them from being so opened.

3. In an internal combustion engine, a plurality of engine cylinders, pistons in said cylinders, exhaust valves for said cylinders, means for normally actuating said exhaust valves at predetermined points @between the ends of the working strokes of said pistons, a firing circuit, an a switch device in said circuit controlled by said latter means. a

In testimony whereof, I sign this specification in the presence of two witnesses.v

FREDERICK PURDY. 

